New stove, wall too hot

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NW Woodheater

New Member
Sep 12, 2014
6
Roslyn, WA
I just had a Jotul F45 with a flue collar heat shield installed with assurance that it would fit the current 50x36 inch floor pad and the installation met specs. The wall behind the stove is just drywall. As I've gone through the break-in fires, where the single wall pipe exits the stove the wall gets very hot and stays hot for about 2.5 feet. The pipe is about 8.5 inches from the wall as it exits the stove and about 14 inches after an elbow to meet the previously installed chimney. The stove needs to be set close to the wall to get the required 16 inch clearance from the door opening to the front of the pad. As I review the installation diagrams from Jotul, it appears that the pipe can't be closer than 10 inches from the unprotected wall. Am I reading that correctly? The installer said it's measured from the middle of the pipe. I'm measuring from the wall to the start of the pipe.

I've considered installing ceramic tile behind the stove over the drywall to address the heat issue. According to the manual, the rear of the stove with a single wall connector and flue collar heat shield can be as little as 4 inches from a protected wall. Would a ceramic tile wall meet that definition? The wall has a wooden stair railing about 7 feet above the stove and so a ceramic tile wall wouldn't cover the railing. I'm not clear how far the pipe must be from the stair railing. After that, the pipe goes up unimpeded about 18-20 feet and exits the ceiling.

Or, do I just need to go with double wall pipe? I want this to meet all installation requirements. If I need to have double wall near the wall and stair railing, should it go all of the way up or would it be OK to transition back to the single wall after the stair railing?

Thank you for your help.
 

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You have cause for concern. Single wall pipe needs to be at least 18" from the wall. For that long run I would definitely switch to double-wall connector. That will reduce heat radiating off of the pipe, bring down the clearance requirements for the stove and alleviate the concern about the clearance to the stairway railing and banister. It will also allow the flue gases to stay hotter and reduce creosote accumulation.
 
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Yes. The 18" minimum clearance for single wall is a code, manufacturer and safety requirement. The flue collar heat shield offers some protection, but not above it where the pipe is angling away from the wall.
 
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I would be seriously concerned if your installer didn't know this! 18" clearance for single wall pipe is a must, it's always been this way. This measurement is taken from the edge of the pipe, not the center. There are dimensions given in the manual for center line of flue, but you also have to read the key properly. This dimension changes depending on double wall or single wall pipe.
 
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Putting ceramic tile there won't necessarily do the job. Or, it might, but probably won't meet code. The tile may be able to conduct the heat right through itself to the wall.

You could put up metal shielding behind that pipe. But, in that installation, from the photo, I would bite the bullet and just switch out the pipe for double-walled pipe. I did this in my case, and the wall is barely warm to the touch when the stove is going full-blast. It costs a little, but you only have to do it once. I held off for quite a while, not wanting to spend the $$. I am glad I finally did.
 
I would have to say your 'installer' is a hack. The single wall pipe has no clue what it is hooked up to in any way so the stove has nothing to do with the clearance of the stack pipe. Down load the NFPA code for 2005 the newest one that is free to do that a simple search on the web will find it. Read it and believe it because if you ever have a fire and the install does not meet code kiss away the ins co check as it will never happen. I have a highly reflective 0.093 thick brushed aluminum heat shield on metal 2X3s mounted to the wall and the closest clearance is 11 inches to the wall and cool to the touch because it reflects the heat. and has a very good air path to carry heat away. Mine is a bit under code but testing has told me if cool to the touch with stove cranking it will not be a problem.
 
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The stove needs to be set close to the wall to get the required 16 inch clearance from the door opening to the front of the pad
How was this measurement taken? I don't know for sure, but I think you can measure from the lowest point on the bottom front of the stove, downward at an angle to the combustible floor in front of the pad; That might give you a few more inches to move the stove/connector pipe forward enough to where you've got a straighter run, but it appears that double-wall connector will still be necessary.
18" minimum clearance for single wall is a code, manufacturer and safety requirement.
Is 18" NFPA 211? The F45 manual appears to have 16" there. In that case, would 211 supercede the manual?
 
Perhaps the dealer was trying to save you some money? Double wall connector will solve most issues with this installation.
Is 18" NFPA 211? The F45 manual appears to have 16" there. In that case, would 211 supercede the manual?

I'm not sure how Jotul justifies that. It could be a typo. As soon as the pipe leaves the stove it is NFPA and the stove pipe mfg.'s domain.

New stove, wall too hot
 
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Perhaps the dealer was trying to save you some money? Double wall connector will solve most issues with this installation.


I'm not sure how Jotul justifies that. It could be a typo. As soon as the pipe leaves the stove it is NFPA and the stove pipe mfg.'s domain.

View attachment 138700

Is the above table 9.5.1.1 showing that the clearance must be 18 inches from NFPA 211?

And I'm not clear what typo is being referred to. Jotul's manual says the minimum floor protection in the US is 16 inches from the door opening, and shows a diagram of lines straight from the door to the front of the pad.
 
Just FYI for everyone and to keep the terminology clear. NFPA is the National Fire Protection Association. It's made up of industry experts and regularly publishes/maintains recommended detailed standards on many aspects of fire prevention. It is not a government agency, and has absolutely no regulatory/enforcement authority. The standards published by the NFPA, including our very favorite NFPA 211, are just that...standards recommended by a non-governmental body of subject matter experts. NFPA standards are not codes enforceable by law. Many local jurisdictions around the country have adopted NFPA standards basically word for word when putting out their own local code requirements, but many have not. NFPA does no testing whatever of materials or anything else. NFPA 211 is an interesting and authoritative document, but isn't the final answer. The final answer comes from the appliance manufacturer's documentation and the local government Authority Having Jurisdiction...this may be an agency of the city, the county, or the state that issues building, safety, and mechanical codes which are legal requirements. Just want us to be using the correct terminology and to know where the "final answer" can be found. Rick
 
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I've considered installing ceramic tile behind the stove over the drywall to address the heat issue. According to the manual, the rear of the stove with a single wall connector and flue collar heat shield can be as little as 4 inches from a protected wall. Would a ceramic tile wall meet that definition?

No. A "protected wall" is one with a properly built and installed heat shield. This is basically any non-combustible material installed with a 1" air gap between it and the wall and installed such that it freely ventilates to allow natural convection of air to travel continuously between the wall and the shield. Any allowed reduction of minimum clearance to a combustible surface by installation of a proper wall shield should be clearly spelled out in the appliance manufacturer's documentation. Applying ceramic tile directly to the wall is a waste of time and tile. Rick
 
would 211 supercede the manual?

Can't happen. Manufacturer's documentation for the specific appliance is based on supervised and certified testing for the model. NFPA recommended standards are not model-specific, nor are they updated very frequently. Manufacturer's documentation for the specific appliance trumps anything found in an NFPA publication.
 
I would be seriously concerned if your installer didn't know this! 18" clearance for single wall pipe is a must, it's always been this way. This measurement is taken from the edge of the pipe, not the center. There are dimensions given in the manual for center line of flue, but you also have to read the key properly. This dimension changes depending on double wall or single wall pipe.


not always.. if the stove has been tested at lower numbers it typically trumps nfpa code (if your locals support you)
example, BK sirocco 20 has a 12" clearance (sw to combustibles)
 
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The stove lists an unprotected wall clearance to the rear wall as 16" with single wall pipe. I am not sure how they come up with this, but there you have it. But the single-wall pipe needs to be 18" from the wall, regardless of the stove, unless it is shielded.
 
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The Jotul manual appears to show that with a double wall connector I can go as close as 6 inches from the rear unprotected wall, correct? So, that looks like it would solve all of my problems.
 

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Yes, that's what it looks like to me. Illustration N in the manual at 4.6 on page 13. 6" from the stove back to the wall. Double-wall stove pipe will get you there for that particular measurement. Make sure everything else checks out OK too. Double-wall pipe will serve you well in this installation, anyway. I'm surprised it wasn't recommended by your installer. Rick
 
I was willing to pay for double wall pipe if it was needed, but was (at the time) happy to avoid that extra cost. With all that's been involved, I sure wish they'd put that in when it the stove was installed. Thanks for the feedback and advice.
 
not always.. if the stove has been tested at lower numbers it typically trumps nfpa code (if your locals support you)
example, BK sirocco 20 has a 12" clearance (sw to combustibles)
Really?
I didn't think Blaze King was giving single wall clearances, because they intend for it to installed with double wall pipe.
 
Yes stove testing can always trump nfpa 211 it rarely changes the 18" rule but it can and does occasionally.
 
not always.. if the stove has been tested at lower numbers it typically trumps nfpa code (if your locals support you)
example, BK sirocco 20 has a 12" clearance (sw to combustibles)
I don't think it changes the rule at all. I just checked the manual and it looks like the Sirocco 20 has a 6" rear clearance but that might equate to 12" from the back of the stove top. This is because the flue collar is not at the back of the stove. But just because the stove can be installed with single-wall at this close distance, it doesn't mean the single-wall pipe clearance is correct unless either the pipe or the wall is properly shielded wherever the clearance is less than 18".

So yes, you can install the stove per mfg. tested clearance, but the single-wall pipe or the wall will still need to be correctly shielded to be safe and according to code. In my book, the heat loss of the single-wall pipe makes this a moot point for the OP's install. It should be done with double-wall both for safety but also to reduce creosote condensation.
 
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Really?
I didn't think Blaze King was giving single wall clearances, because they intend for it to installed with double wall pipe.

Page 12 of the manual is confusing, it shows a 12" clearance to the pipe, but now i see the astrix saying check with local codes and pipe makers info..
why would the 12" clearance number be published in the manual if it hasn't been tested for that and approved?
the model in the manual doesn't say for double walled pipe and
the next page describes the connector as 24/26 ga black/blue steel
 
The stove is allowed to be that close to combustibles, but only if the connector pipe that's being used can also be. Therefore double wall pipe must be used in order to have the stove at this minimum clearance.
 
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